Be very careful with the wife mod. Uninstallation can be extremely expensive. Wife mods have been known to take the Jeep and all other mods during the uninstall process. Also, make sure you service your wife mod properly as often as humanly possible. Wife mods not properly serviced may malfunction or uninstall themselves at any time.

If I am on the same bolt . An 8mm wrench is what seems to be the most popular answer but for the actual bolt size , Sorry . I ended up with a nice skinned knuckle when the 8mm wrench I was using slipped so I tried a 5/16. It very well could of just been the quality of my wrench but the 5/16 fit tighter and was able to loosen the bolt.
Now is when the math usually is posted to explain how little the difference actually is and should make no difference . Either way 5/16 is smaller , who cares. Its just another option.

EDIT: After all of that I think you are looking for the actual bolt size , oops

I can't remember if it's 1" or 1-1/4" though.
There's plenty of room for the 1/2" standard head bolt on the transfer case side of the yoke too. No need to get allen bolts.

The stock bolts are hex head flange bolts (maybe screws, I always mix the nomenclature up). There is no Allen wrench involved. I have used regular hex head cap screws but prefer the flange version so I can use a socket and ratchet rather than a open end wrench.

The stock bolts are hex head flange bolts (maybe screws, I always mix the nomenclature up). There is no Allen wrenches involved.

The stock bolt heads are 5/16ths with a flange andr a 5/16ths thread bolt.
All I was saying is a standard 5/16ths bolt with a 1/2" head will fit, there's no need to try to find something with a small head (like an Allen or whatever).

The stock bolt heads are 5/16ths with a flange andr a 5/16ths thread bolt.
All I was saying is a standard 5/16ths bolt with a 1/2" head will fit, there's no need to try to find something with a small head (like an Allen or whatever).

Okay. I was confused with the Allen part but that clears it up. I still prefer the flange bolts but to each their own.

I just checked again both axle yokes are 1/4 NF I suppose there could be different yokes of the 44 I am sure is different???? Never really paid that much attention to the kit. Just bought and installed...Jon